Abstract During the last decade, the maximum capacity of an optical fiber transmission line more than doubled every year to match the fast-growing communication need. The technology break through in dry fiber fabrication opens the possibility for fiber bandwidth all the way from 1.3

none

Abstract During the last decade, the fast-growing communication need has promoted the development of the wavelength of 1.3 mm~1.6 mm laser light source. The Cr4+ doped YAG solid-state laser has potential to meet this super wideband demand. In addition, solid state laser has the merits of high laser beam quality, long lifetime, compact, and simple structure. In this thesis, crystal fiber was used as the laser gain medium, and coated with optical thin film at its end facets as the laser cavity. Using this configuration, the volume and cost of the laser can be appreciatively reduced, and the heat dissipation can be improved. The laser-heated-pedestal-growth method was used to grow crystal fiber, which can obtain small diameter at very fast rate and accurate control. High quality Cr4+:YAG crystal fiber with the smallest diameter of 50 mm was grown. A glass-packaged technique clothes the crystal fiber with a core diameter as small as 11 mm. Outside the glass clad Cr4+:YAG crystal fiber, Al-Cu alloy was employed as the heat sink to improve heat dissipation. After grinding, polishing, and coating of this device, the Cr4+:YAG crystal fiber laser was fabricated. Some characteristics of Cr4+:YAG crystal fiber, such as the distribution of Cr2O3 and CaO doping concentration, fluorescence intensity, refraction index, propagation loss, and absorption coefficient were measured and analyzed. In the meanwhile, some simulations of the laser output power depending on the absorption coefficient, propagation loss, output coupling, crystal fiber diameter, and crystal boundary temperature were discussed.